How can you differentiate between ionic and covenants compounds only by formula?
Answers
The two main types of chemical bonds are ionic and covalent bonds. An ionic bond essentially donates an electron to the other atom participating in the bond, while electrons in a covalent bond are shared equally between the atoms. The only pure covalent bonds occur between identical atoms.
Answer:
MENU
Home
Search
Close
Search the site
Search here...
GO
Science, Tech, Math
Humanities
Languages
Resources
About Us
Contact Us
Editorial Guidelines
Privacy Policy
Ad
Science, Tech, Math › Science
Ionic vs Covalent Bonds - Understand the Difference
Share
Covalent bond
Electrons in a covalent bond are shared equally, while electrons in an ionic bond spend more time closer to one atom than the other. PASIEKA / Getty Images
By Anne Marie Helmenstine, Ph.D.
Updated January 23, 2020
A molecule or compound is made when two or more atoms form a chemical bond, linking them together. The two types of bonds are ionic bonds and covalent bonds. The distinction between them has to do with how equally the atoms participating in the bond share their electrons.
Ionic Bonds
In an ionic bond, one atom essentially donates an electron to stabilize the other atom. In other words, the electron spends most of its time close to the bonded atom. Atoms that participate in an ionic bond have different electronegativity values from each other. A polar bond is formed by the attraction between oppositely-charged ions. For example, sodium and chloride form an ionic bond, to make NaCl, or table salt. You can predict an ionic bond will form when two atoms have different electronegativity values and detect an ionic compound by its properties, including a tendency to dissociate into ions in water.
Covalent Bonds
In a covalent bond, the atoms are bound by shared electrons. In a true covalent bond, the electronegativity values are the same (e.g., H2, O3), although in practice the electronegativity values just need to be close. If the electron is shared equally between the atoms forming a covalent bond, then the bond is said to be nonpolar. Usually, an electron is more attracted to one atom than to another, forming a polar covalent bond. For example, the atoms in water, H2O, are held together by polar covalent bonds. You can predict a covalent bond will form between two nonmetallic atoms. Also, covalent compounds may dissolve in water, but don't dissociate into ions.
Ionic vs Covalent Bonds Summary
Here's a quick summary of the differences between ionic and covalent bonds, their properties, and how to recognize them:
Ionic Bonds Covalent Bonds
Description Bond between metal and nonmetal. The nonmetal attracts the electron, so it's like the metal donates its electron to it. Bond between two nonmetals with similar electronegativities. Atoms share electrons in their outer orbitals.
Polarity High Low
Shape No definite shape Definite shape
Melting Point High Low
Boiling Point High Low
State at Room Temperature Solid Liquid or Gas
Examples Sodium chloride (NaCl), Sulfuric Acid (H 2SO 4 ) Methane (CH 4), Hydrochloric acid (HCl)
Chemical Species Metal and nometal (remember hydrogen can act either way) Two nonmetals
Do you understand? Test your comprehension with this quiz.
Key Points
The two main types of chemical bonds are ionic and covalent bonds.
An ionic bond essentially donates an electron to the other atom participating in the bond, while electrons in a covalent bond are shared equally between the atoms.
The only pure covalent bonds occur between identical atoms. Usually, there is some polarity (polar covalent bond) in which the electrons are shared, but spend more time with one atom than the other.
Ionic bonds form between a metal and a nonmetal. Covalent bonds form between two nonmetals.
Cite this Article
Watch Now: How To Make A Chemical Bond
A polar bond is a type of covalent chemical bond.
Polar Bond Definition and Examples
Salt shaker, close-up
Ionic Compound Properties, Explained
A 3D example of an ionic compound.
Formulas of Ionic Compounds
A diagram showing how ionic bonds are formed.
Examples of Ionic Bonds and Compounds
Someone pouring water into a cup
Weak Acid Definition and Examples in Chemistry
Carbon dioxide is an example of a nonpolar molecule.
Nonpolar Molecule Definition and Examples
Transparent Sphere Underwater
Why Is Water a Polar Molecule?
The formation of ionic compounds is exothermic because the ionic bonds give stability to the atoms. The excess energy is released as heat.
Why the Formation of Ionic Compounds Is Exothermic
Water molecule
What Causes Hydrogen Bonding?
Examples of covalent compounds: ammonia, hydrogen, and water
What Are Some Examples of Covalent Compounds?
Water molecules
Hydrogen Bond Definition and Examples
Metallic Bond: Definition, Properties, and Examples
Home
Learn Something New Every Day